From 329b6653ffbb29b47409a923a7fbb3bd3aff074f Mon Sep 17 00:00:00 2001 From: Jianfeng Tan Date: Thu, 5 Sep 2019 15:03:41 +0800 Subject: Implement /proc/net/tcp6 Fixes: #829 Signed-off-by: Jianfeng Tan Signed-off-by: Jielong Zhou --- pkg/sentry/fs/proc/net.go | 135 ++++++++++++++++++++++++++++++---------------- 1 file changed, 89 insertions(+), 46 deletions(-) (limited to 'pkg/sentry/fs') diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go index 5e28982c5..c80c770b5 100644 --- a/pkg/sentry/fs/proc/net.go +++ b/pkg/sentry/fs/proc/net.go @@ -66,7 +66,7 @@ func (p *proc) newNetDir(ctx context.Context, k *kernel.Kernel, msrc *fs.MountSo if s.SupportsIPv6() { contents["if_inet6"] = seqfile.NewSeqFileInode(ctx, &ifinet6{s: s}, msrc) contents["ipv6_route"] = newStaticProcInode(ctx, msrc, []byte("")) - contents["tcp6"] = newStaticProcInode(ctx, msrc, []byte(" sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode")) + contents["tcp6"] = seqfile.NewSeqFileInode(ctx, &netTCP6{k: k}, msrc) contents["udp6"] = newStaticProcInode(ctx, msrc, []byte(" sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode")) } } @@ -310,44 +310,51 @@ func networkToHost16(n uint16) uint16 { return usermem.ByteOrder.Uint16(buf[:]) } -func writeInetAddr(w io.Writer, a linux.SockAddrInet) { - // linux.SockAddrInet.Port is stored in the network byte order and is - // printed like a number in host byte order. Note that all numbers in host - // byte order are printed with the most-significant byte first when - // formatted with %X. See get_tcp4_sock() and udp4_format_sock() in Linux. - port := networkToHost16(a.Port) - - // linux.SockAddrInet.Addr is stored as a byte slice in big-endian order - // (i.e. most-significant byte in index 0). Linux represents this as a - // __be32 which is a typedef for an unsigned int, and is printed with - // %X. This means that for a little-endian machine, Linux prints the - // least-significant byte of the address first. To emulate this, we first - // invert the byte order for the address using usermem.ByteOrder.Uint32, - // which makes it have the equivalent encoding to a __be32 on a little - // endian machine. Note that this operation is a no-op on a big endian - // machine. Then similar to Linux, we format it with %X, which will print - // the most-significant byte of the __be32 address first, which is now - // actually the least-significant byte of the original address in - // linux.SockAddrInet.Addr on little endian machines, due to the conversion. - addr := usermem.ByteOrder.Uint32(a.Addr[:]) - - fmt.Fprintf(w, "%08X:%04X ", addr, port) -} +func writeInetAddr(w io.Writer, family int, i linux.SockAddr) { + switch family { + case linux.AF_INET: + var a linux.SockAddrInet + if i != nil { + a = *i.(*linux.SockAddrInet) + } -// netTCP implements seqfile.SeqSource for /proc/net/tcp. -// -// +stateify savable -type netTCP struct { - k *kernel.Kernel -} + // linux.SockAddrInet.Port is stored in the network byte order and is + // printed like a number in host byte order. Note that all numbers in host + // byte order are printed with the most-significant byte first when + // formatted with %X. See get_tcp4_sock() and udp4_format_sock() in Linux. + port := networkToHost16(a.Port) + + // linux.SockAddrInet.Addr is stored as a byte slice in big-endian order + // (i.e. most-significant byte in index 0). Linux represents this as a + // __be32 which is a typedef for an unsigned int, and is printed with + // %X. This means that for a little-endian machine, Linux prints the + // least-significant byte of the address first. To emulate this, we first + // invert the byte order for the address using usermem.ByteOrder.Uint32, + // which makes it have the equivalent encoding to a __be32 on a little + // endian machine. Note that this operation is a no-op on a big endian + // machine. Then similar to Linux, we format it with %X, which will print + // the most-significant byte of the __be32 address first, which is now + // actually the least-significant byte of the original address in + // linux.SockAddrInet.Addr on little endian machines, due to the conversion. + addr := usermem.ByteOrder.Uint32(a.Addr[:]) + + fmt.Fprintf(w, "%08X:%04X ", addr, port) + case linux.AF_INET6: + var a linux.SockAddrInet6 + if i != nil { + a = *i.(*linux.SockAddrInet6) + } -// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. -func (*netTCP) NeedsUpdate(generation int64) bool { - return true + port := networkToHost16(a.Port) + addr0 := usermem.ByteOrder.Uint32(a.Addr[0:4]) + addr1 := usermem.ByteOrder.Uint32(a.Addr[4:8]) + addr2 := usermem.ByteOrder.Uint32(a.Addr[8:12]) + addr3 := usermem.ByteOrder.Uint32(a.Addr[12:16]) + fmt.Fprintf(w, "%08X%08X%08X%08X:%04X ", addr0, addr1, addr2, addr3, port) + } } -// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. -func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { +func commonReadSeqFileDataTCP(n seqfile.SeqHandle, k *kernel.Kernel, ctx context.Context, h seqfile.SeqHandle, fa int, header []byte) ([]seqfile.SeqData, int64) { // t may be nil here if our caller is not part of a task goroutine. This can // happen for example if we're here for "sentryctl cat". When t is nil, // degrade gracefully and retrieve what we can. @@ -358,7 +365,7 @@ func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se } var buf bytes.Buffer - for _, se := range n.k.ListSockets() { + for _, se := range k.ListSockets() { s := se.Sock.Get() if s == nil { log.Debugf("Couldn't resolve weakref with ID %v in socket table, racing with destruction?", se.ID) @@ -369,7 +376,7 @@ func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se if !ok { panic(fmt.Sprintf("Found non-socket file in socket table: %+v", sfile)) } - if family, stype, _ := sops.Type(); !(family == linux.AF_INET && stype == linux.SOCK_STREAM) { + if family, stype, _ := sops.Type(); !(family == fa && stype == linux.SOCK_STREAM) { s.DecRef() // Not tcp4 sockets. continue @@ -384,22 +391,22 @@ func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se fmt.Fprintf(&buf, "%4d: ", se.ID) // Field: local_adddress. - var localAddr linux.SockAddrInet + var localAddr linux.SockAddr if t != nil { if local, _, err := sops.GetSockName(t); err == nil { - localAddr = *local.(*linux.SockAddrInet) + localAddr = local } } - writeInetAddr(&buf, localAddr) + writeInetAddr(&buf, fa, localAddr) // Field: rem_address. - var remoteAddr linux.SockAddrInet + var remoteAddr linux.SockAddr if t != nil { if remote, _, err := sops.GetPeerName(t); err == nil { - remoteAddr = *remote.(*linux.SockAddrInet) + remoteAddr = remote } } - writeInetAddr(&buf, remoteAddr) + writeInetAddr(&buf, fa, remoteAddr) // Field: state; socket state. fmt.Fprintf(&buf, "%02X ", sops.State()) @@ -465,7 +472,7 @@ func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se data := []seqfile.SeqData{ { - Buf: []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode \n"), + Buf: header, Handle: n, }, { @@ -476,6 +483,42 @@ func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se return data, 0 } +// netTCP implements seqfile.SeqSource for /proc/net/tcp. +// +// +stateify savable +type netTCP struct { + k *kernel.Kernel +} + +// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. +func (*netTCP) NeedsUpdate(generation int64) bool { + return true +} + +// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. +func (n *netTCP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { + header := []byte(" sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode \n") + return commonReadSeqFileDataTCP(n, n.k, ctx, h, linux.AF_INET, header) +} + +// netTCP6 implements seqfile.SeqSource for /proc/net/tcp6. +// +// +stateify savable +type netTCP6 struct { + k *kernel.Kernel +} + +// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate. +func (*netTCP6) NeedsUpdate(generation int64) bool { + return true +} + +// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData. +func (n *netTCP6) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { + header := []byte(" sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode\n") + return commonReadSeqFileDataTCP(n, n.k, ctx, h, linux.AF_INET6, header) +} + // netUDP implements seqfile.SeqSource for /proc/net/udp. // // +stateify savable @@ -529,7 +572,7 @@ func (n *netUDP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se localAddr = *local.(*linux.SockAddrInet) } } - writeInetAddr(&buf, localAddr) + writeInetAddr(&buf, linux.AF_INET, &localAddr) // Field: rem_address. var remoteAddr linux.SockAddrInet @@ -538,7 +581,7 @@ func (n *netUDP) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]se remoteAddr = *remote.(*linux.SockAddrInet) } } - writeInetAddr(&buf, remoteAddr) + writeInetAddr(&buf, linux.AF_INET, &remoteAddr) // Field: state; socket state. fmt.Fprintf(&buf, "%02X ", sops.State()) -- cgit v1.2.3